The modern communications era has brought about a tremendous expansion of wireline and wireless networks. Computer networks, television networks, and telephony networks are experiencing an unprecedented technological expansion, fueled by consumer demand. Wireless and mobile networking technologies have addressed related consumer demands, while providing more flexibility and immediacy of information transfer.
Current and future networking technologies continue to facilitate ease of information transfer and convenience to users. One area in which there is a demand to increase ease of information transfer relates to the delivery of services to a user of a mobile terminal. The services may be in the form of a particular media or communication application desired by the user, such as a music player, a game player, an electronic book, short messages, email, etc. The services may also be in the form of interactive applications in which the user may respond to a network device in order to perform a task or achieve a goal. The services may be provided from a network server or other network device, or even from the mobile terminal such as, for example, a mobile telephone, a mobile television, a mobile gaming system, etc.
In music applications, extraction of beat information can be of fundamental importance. Beat is an important rhythmic property common to all music. The sensation of beat is a fundamental enabler for dancing and enjoying music in general. Detecting beats in music enables applications to calculate musical tempo in units of beats per minute (BPM) for a particular piece of music. Meanwhile tatum, which is a term that is short for “temporal atom”, is the shortest durational value repeatedly present in a music signal. The beat and the tatum are two examples of metrical levels found in music, and in any given piece of music there are multiple nested levels of metrical structure, or meter, present. The tatum is the lowest metrical level, the root from which all other metrical levels can be derived, while the beat is the most salient level. Since the concept of musical beat is universal, any device or application capable of extracting beat and tatum information from music would have wide appeal and utility. For example, such a device or application would be useful in music applications such as music playback, music remixing, music visualization, music synchronization, music classification, music browsing, music searching and numerous others.
Because of the recognized utility of beat detection, many proposals have been made which are directed to enabling beat detection. However, beat tracking from sampled audio is a nontrivial problem. An example of a conventional beat detection approach includes bandfiltering the lowest frequencies in a music signal and then, for example, calculating an autocorrelation of the extracted bass band. Unfortunately this and other conventional techniques do not give satisfactory results. Accordingly, there is a need for a novel beat tracking algorithm that provides improved beat tracking capability.
Furthermore, such an improved beat tracker should be employable in mobile environments since it is increasingly common for music applications to be utilized in conjunction with mobile devices such as mobile telephones, mobile computers, MP3 players, and numerous other mobile terminals.